From: "NeilBrown" <neilb@suse.de>
To: Chuck Lever <chuck.lever@oracle.com>, Jeff Layton <jlayton@kernel.org>
Cc: linux-nfs@vger.kernel.org, Olga Kornievskaia <kolga@netapp.com>,
Dai Ngo <Dai.Ngo@oracle.com>, Tom Talpey <tom@talpey.com>
Subject: [PATCH 1/4 v3] nfsd: perform all find_openstateowner_str calls in the one place.
Date: Mon, 11 Mar 2024 09:17:57 +1100 [thread overview]
Message-ID: <171010907730.13576.5751778995820664441@noble.neil.brown.name> (raw)
Currently find_openstateowner_str lookups are done both in
nfsd4_process_open1() and alloc_init_open_stateowner() - the latter
possibly being a surprise based on its name.
It would be easier to follow, and more conformant to common patterns, if
the lookup was all in the one place.
So replace alloc_init_open_stateowner() with
find_or_alloc_open_stateowner() and use the latter in
nfsd4_process_open1() without any calls to find_openstateowner_str().
This means all finds are find_openstateowner_str_locked() and
find_openstateowner_str() is no longer needed. So discard
find_openstateowner_str() and rename find_openstateowner_str_locked() to
find_openstateowner_str().
Signed-off-by: NeilBrown <neilb@suse.de>
---
The previous version of this patch could deadlock on ->cl_lcok as it
called release_openowner() while holding that lock.
This version doesn't.
Subsequent patch in the original series should be unchanged. If needed
I can resent them all after -rc1 is out.
fs/nfsd/nfs4state.c | 93 +++++++++++++++++++--------------------------
1 file changed, 40 insertions(+), 53 deletions(-)
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index ee9aa4843443..3e144b1a1386 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -541,7 +541,7 @@ same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner)
}
static struct nfs4_openowner *
-find_openstateowner_str_locked(unsigned int hashval, struct nfsd4_open *open,
+find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
struct nfs4_client *clp)
{
struct nfs4_stateowner *so;
@@ -558,18 +558,6 @@ find_openstateowner_str_locked(unsigned int hashval, struct nfsd4_open *open,
return NULL;
}
-static struct nfs4_openowner *
-find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open,
- struct nfs4_client *clp)
-{
- struct nfs4_openowner *oo;
-
- spin_lock(&clp->cl_lock);
- oo = find_openstateowner_str_locked(hashval, open, clp);
- spin_unlock(&clp->cl_lock);
- return oo;
-}
-
static inline u32
opaque_hashval(const void *ptr, int nbytes)
{
@@ -4855,34 +4843,46 @@ nfsd4_find_and_lock_existing_open(struct nfs4_file *fp, struct nfsd4_open *open)
}
static struct nfs4_openowner *
-alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
- struct nfsd4_compound_state *cstate)
+find_or_alloc_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
+ struct nfsd4_compound_state *cstate)
{
struct nfs4_client *clp = cstate->clp;
- struct nfs4_openowner *oo, *ret;
+ struct nfs4_openowner *oo, *new = NULL;
- oo = alloc_stateowner(openowner_slab, &open->op_owner, clp);
- if (!oo)
- return NULL;
- oo->oo_owner.so_ops = &openowner_ops;
- oo->oo_owner.so_is_open_owner = 1;
- oo->oo_owner.so_seqid = open->op_seqid;
- oo->oo_flags = 0;
- if (nfsd4_has_session(cstate))
- oo->oo_flags |= NFS4_OO_CONFIRMED;
- oo->oo_time = 0;
- oo->oo_last_closed_stid = NULL;
- INIT_LIST_HEAD(&oo->oo_close_lru);
+retry:
spin_lock(&clp->cl_lock);
- ret = find_openstateowner_str_locked(strhashval, open, clp);
- if (ret == NULL) {
- hash_openowner(oo, clp, strhashval);
- ret = oo;
- } else
- nfs4_free_stateowner(&oo->oo_owner);
-
+ oo = find_openstateowner_str(strhashval, open, clp);
+ if (!oo && new) {
+ hash_openowner(new, clp, strhashval);
+ spin_unlock(&clp->cl_lock);
+ return new;
+ }
spin_unlock(&clp->cl_lock);
- return ret;
+
+ if (oo && !(oo->oo_flags & NFS4_OO_CONFIRMED)) {
+ /* Replace unconfirmed owners without checking for replay. */
+ release_openowner(oo);
+ oo = NULL;
+ }
+ if (oo) {
+ if (new)
+ nfs4_free_stateowner(&new->oo_owner);
+ return oo;
+ }
+
+ new = alloc_stateowner(openowner_slab, &open->op_owner, clp);
+ if (!new)
+ return NULL;
+ new->oo_owner.so_ops = &openowner_ops;
+ new->oo_owner.so_is_open_owner = 1;
+ new->oo_owner.so_seqid = open->op_seqid;
+ new->oo_flags = 0;
+ if (nfsd4_has_session(cstate))
+ new->oo_flags |= NFS4_OO_CONFIRMED;
+ new->oo_time = 0;
+ new->oo_last_closed_stid = NULL;
+ INIT_LIST_HEAD(&new->oo_close_lru);
+ goto retry;
}
static struct nfs4_ol_stateid *
@@ -5331,27 +5331,14 @@ nfsd4_process_open1(struct nfsd4_compound_state *cstate,
clp = cstate->clp;
strhashval = ownerstr_hashval(&open->op_owner);
- oo = find_openstateowner_str(strhashval, open, clp);
+ oo = find_or_alloc_open_stateowner(strhashval, open, cstate);
open->op_openowner = oo;
- if (!oo) {
- goto new_owner;
- }
- if (!(oo->oo_flags & NFS4_OO_CONFIRMED)) {
- /* Replace unconfirmed owners without checking for replay. */
- release_openowner(oo);
- open->op_openowner = NULL;
- goto new_owner;
- }
+ if (!oo)
+ return nfserr_jukebox;
status = nfsd4_check_seqid(cstate, &oo->oo_owner, open->op_seqid);
if (status)
return status;
- goto alloc_stateid;
-new_owner:
- oo = alloc_init_open_stateowner(strhashval, open, cstate);
- if (oo == NULL)
- return nfserr_jukebox;
- open->op_openowner = oo;
-alloc_stateid:
+
open->op_stp = nfs4_alloc_open_stateid(clp);
if (!open->op_stp)
return nfserr_jukebox;
--
2.43.0
next reply other threads:[~2024-03-10 22:18 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-03-10 22:17 NeilBrown [this message]
2024-03-11 11:34 ` [PATCH 1/4 v3] nfsd: perform all find_openstateowner_str calls in the one place Jeff Layton
2024-04-02 21:03 ` Chuck Lever
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